1. Field of the Invention
Aspects of the present invention relate to a lithium rechargeable battery.
2. Description of the Related Art
Generally, rechargeable batteries, for use in portable devices, such as, video cameras, portable phones, portable computers, and others, have been actively researched. The rechargeable batteries include a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, a lithium rechargeable battery, and others. Among these rechargeable batteries, the lithium rechargeable battery has a large capacity, a compact size, a high operation voltage, and a high energy density per unit weight, so it is widely used for the latest electronic devices.
When an external impact, such as a drop, occurs to a cylindrical-type lithium rechargeable battery, an electrode assembly of the battery is liable to fluctuate or rotate inside the battery can. When the electrode assembly fluctuates or rotates by a predetermined extent, an electrode tab, attached to the electrode assembly, fluctuates or rotates simultaneously. In this case, the weld between the cathode tab and a safety vent can be broken, and an internal circuit of the battery can be electrically disconnected.
In addition, the cylindrical lithium rechargeable battery includes a beading part inside the battery, between an upper insulation plate and a lower end of a gasket. Thus, there is a problem in that the cathode tab contacts the beading part, to cause an electrical short, when the lithium rechargeable battery is impacted by an external shock, or during the welding process of the cathode tab and a cap assembly.